Centimeter-long Ta3N5 nanobelts: synthesis, electrical transport, and photoconductive properties

Centimeter-long Ta3N5 nanobelts were synthesized by a reaction of centimeter-long TaS3 nanobelt templates with flowing NH3 at 800 °C for 2 h. The nanobelts have cross-sections of about 50 × 100 nm2, and lengths up to 0.5 cm. A field effect transistor (FET) made of a single Ta3N5 nanobelt was fabricated on silica/silicon substrate. The electric transport of the individual nanobelt revealed that the nanobelt is a semiconductor with a room-temperature resistivity of 11.88 Ω m, and can be fitted well with an empirical formula ρ = 10831 exp(−T/43.8) − 22.6, where ρ is resistivity (Ω m) and T is absolute temperature (K). The FET showed decent photoconductive performance under light irradiation in the range 250–630 nm. The photocurrent increased by nearly 10 times the dark current under 450 nm light irradiation at an applied voltage of 5.0 V. (paper)